[（x+1）(x+4)][(x+2)(x+3)]+1=(x*x+5x+4)(x*x+5x+6)+1令x*x+5x=y=(y+4)(y+6)+1=y*y+10y+24+1=y*y+10y+25=(y+5)*(y+5)=(x*x+5x+5)*(x*x+5x+5) 1/(x-2)+k/(x+2)=3/(x-4) 左边通分可得到： (x+2)/(x^2-4)+k(x-2)/(x^2-...